There has been known a technique, in which an EGR passage connected to an exhaust passage and connected to an intake passage and an EGR control valve installed in the EGR passage are provided, and by performing EGR which introduces a part of exhaust gas into an intake system (an intake line) in accordance with an operating condition, exhaust performance and fuel economy of an internal combustion engine are improved.
For instance, Patent Document 1 discloses a configuration, in which an intake control valve that is disposed in an intake pipe of each cylinder located at a downstream side of a throttle valve and changes an opening area of the intake pipe by flap motion of the intake control valve together with turning motion of a shaft is provided, and an EGR gas ejection hole formed in the intake pipe of each cylinder, which is connected to an EGR passage branching off from an exhaust passage, can be closed by the intake control valve or the shaft.
In such a configuration of Patent Document 1, as long as the EGR gas ejection hole is closed by the intake control valve or the shaft, even if an EGR control valve disposed in the EGR passage is opened, EGR gas does not flow into the intake pipe. Therefore, in an operating condition in which the EGR gas is not introduced into the intake pipe, by filling the EGR passage with the EGR gas while closing the EGR gas ejection hole by the EGR control valve etc., when the operating condition is changed to an operating condition in which the EGR gas is introduced into the intake pipe, by opening the EGR gas ejection hole and opening the EGR control valve at a target opening degree, an EGR ratio can be controlled with a good response.
In the case of Patent Document 1, however, for the control of the EGR, besides the EGR control valve, a component such as the intake control valve which is capable of closing the EGR gas ejection hole is necessary, and this brings a problem of increasing a component count for the EGR control.